In network communication, a sending device sends messages to a receiving device as part of a communication flow. These messages are sent through a number of network devices such as routers and switches to travel from their source to their destination. In a packet-switching network, the transmission, routing, forwarding, and the like of messages between the terminals in the packet-switching network are divided into one or more packets. Thus, all the packets must proceed through these network devices to arrive at the destination.
A common complaint from users of computer networks is that an application is slow. For example, the Outlook response is slow or that the browser is slow. From a network provider and operator standpoint, it is very useful a determination can be made as to which network segment is having a bottleneck. Often times, switches and routers through which packets associated with the applications travel are geographically spread out, thereby making it difficult, if not impossible, to put personnel at each network segment to trace out the timing of the packet so that bottlenecks can be identified.